This invention relates to electrostatic discharge (ESD) protection in systems, such as magnetic disk drives.
One approach to providing ESD protection to ESD sensitive devices in magnetic disk drives, such as a giant magnetoresistive (GMR) sensor in a disk drive read head, involves the use of back-to-back diodes. If these diodes are located in a preamplifier circuit, as they typically are, there is no protection until the head gimbal assembly is completed. The protection at that point is marginal due to the high turn-on potential of the diodes, the high impedance of the turned-on diodes, and their remote location (at the opposite end of the flex circuit from the GMR sensor). Locating the diodes closer to the GMR sensor would only partly mitigate these problems, and would incur significant additional manufacturing cost to implement.